It is desirable to protect chain bearings (the wear surface between the outside diameter of a chain pin and the inside diameter of a chain bushing) by keeping the bearing lubricated and by preventing abrasive material from entering the bearing surface. See, for example, U.S. Pat. No. 4,464,151, issued to Kahl on Aug. 7, 1984, assigned to the assignee of the present invention, and incorporated herein by reference.
It is also desirable to provide a roller sealing arrangement to prevent lubricant efflux from a roller joint and contaminant influx into a roller joint, and to thereby improve the wear characteristics of the roller joint. See, for example, U.S. Pat. No. 5,222,920, issued to Cheesman et al. on Jun. 29, 1993, assigned to the assignee of the present invention, and incorporated herein by reference.
Another sealing arrangement is illustrated in U.S. Pat. No. 4,729,754, issued to Thuerman on Mar. 8, 1988, assigned to the assignee of the present invention, and incorporated herein by reference.